Imidazoline, Thiourea, Amines And Amino Phosphonic Acids Structure-activity Relationship Research Of Organic Corrosion Inhibitors

Corrosion inhibitors play a great role in reducing metal corrosion rate, which is one of the most important means for corrosion and protection field at home and abroad. The corrosion inhibitors’molecular structural parameters have a decisive influence on the corrosion inhibition efficiency. Calculating the structural parameters of corrosion inhibitor by the theoretical calculation such as semi empirical algorithm and theoretical calculation method(DFT), and constructing the relationship between the corrosion inhibition efficiency and the structure parameters by statistic analysis software, and then to predict and optimize the corrosion inhibitor effectiveness, is one of the research hot spots of current corrosion inhibitor, and it has made a lot of research findings. This paper selects26kinds of imidazoline inhibitor sample set、19kinds of thiourea sample set、14kinds of amino phosphonic acid sample set and9kinds of amine organic sample set as the objects of study through the examination of a large body of literature, and wish that it can provide useful information for designing and screening a new inhibitor.This paper uses density functional theory of quantum chemistry for the theoretical calculation method(DFT) on the base of the pre optimization. GaussianView was used the program to construct the initial molecular configuration of those corrosion inhibitors, and the molecule structure of these inhibitors are optimized and the frequency calculation was carried out at the B3LYP6-311++G basis set level.After shows the most stable configurations of inhibitors molecule structure were obtained (vibration analysis have not imaginary frequency), the quantitative structure parameters which have useful information are selected after analysis. Finally constructing the4kinds of corrosion inhibitors’QSAR model by the SPSS19.0statistical analysis software. And a detailed analysis for the QSAR equations on the corrosion relationship between and influence on the structural parameters is made at the end of the paper’s work.Finally, all the QSAR models are summarized, and it shows that all inhibitors in four sample set the nitrogen atom of the charge density has a very big and same influence on the inhibition efficiency without any prior consulation, this is closely related to strong adsorption of the nitrogen atoms which can provide lone electron pair to metal’s orbitals. It provides useful information to the prediction of corrosion inhibitors’efficiency and screening the more excellent inhibitors’performance.